Means for detachable joining of beam elements

ABSTRACT

Means for detachably joining two beam elements by a joint which is resistant to bending and torsion forces. The means comprises two engageable parts, one of which has a portion which may be moved into sliding engagement with a mating recess in the other part, with the sliding engagement occurring at right angles to the longitudinal axis of the beam elements which are detachably joined. A screw passes through one of the parts and threadably engages in the other part to prevent separation of the joined parts.

United States Patent Paul Wedendal Anrau 7, Djursholm, Sweden 830,081

June 3, 1969 June 29, 1971 Inventor Appl. No. Filed Patented MEANS FORDETACHABLE JOINING OF BEAM ELEMENTS 6 Claims, 7 Drawing Figs.

05. CI 287/l89.36R, 287/ 103 Int. Cl Fl6b 3/00 Field of Search..287/l89, 36

F, 20.92 T, 20.92, 103, 54 A, 54 B, 54 C, 189.36

[56] References Cited UNITED STATES PATENTS 2,568,077 9/1951 Loufek287/103 X Primary Examinef-Reinaldo P. Machado Assistant ExaminerWayneL. Shedd Att0mey-Sommers & Young PATENTEU JUN29 I971 FIG. 6 1 FIG 7 H."a. 1 H i! INVENTOR Paul Wedendo I MEANS FOR DETACHABLE JOINING F BEAMELEMENTS BACKGROUND OF THE INVENTION One intended field of use for theinvention is crownwork and bridgework by a dentist, where the dentistmust often combine parts of the system. Previously this has normallybeen carried out with the help of soldering with gold solder and hasbeen carried out by dental technicians on a working model in the finalstages of the work. The construction thus obtained must be cemented toabutment teeth. In certain cases, for example when the abutment teethdiverge considerably from each other, it may be necessary to make theconstruction in separate parts which are individually cemented andfinally screwed together in the patients mouth. A considerable number ofscrews of different dimensions must then be available. It is alsoobvious that the demand for accurate shaping of the contact surfaces isthen extremely great, particularly if these must be designed so that thejoining function of the screw joint is assisted. The invention offers asolution with many advantages for the fields of use indicated.

SUMMARY OF THE INVENTION According to the invention the joining meansconsists of two parts, one part having a portion thereof which isinsertable into an aperture in the other part in a directionperpendicular to the axial direction of the beam element. Said one partis provided with projecting guiding strips which are parallel to thedirection of insertion and the other part is provided with correspondinggrooves which exactly receive the guiding strips on said one part. Theinsertion is limited by a plate on the first part attached to a baseportion. At least one screw passing through holes in the end part of theplate then attaches the plate to a base portion of the other part in atleast one threaded channel in this. In this way detachable locking ofthe elements is obtained which are attached to the base parts in stripsor the like on these parts.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be furtherexplained with reference to one embodiment which is shown in theaccompanying drawings in which 1 7. FIG. I shows one of the two parts ofa joint vertically in side elevation;

FIG. 2 in cross section along the section line 2-2;

FIG. 3 shows the other of the two parts of a joint vertically in asection through the side projection;

FIG. 4 in cross section in horizontal projection;

FIG. 5 shows a connecting screw for the screw joint; and

FIGS. 6 and 7 show the two joint parts in perspective.

DESCRIPTION OF THE PREFERRED EMBODIMENT One part of the joint accordingto FIGS. 1 and 2 consists of a base part B I, from which a projectingweb portion L I extends perpendicularly. At one end of the base part aplate P is arranged which covers the projection L I and is integrallyjoined to this. At the end of the plate is a hole I-I, suitably conical,for a screw. The part is provided approximately centrally on both sidesurfaces with guiding strips SL which extend perpendicularly to theplate P. These guiding strips suitably have a semicircular cross sectionaccording to the drawings. The part is intended to be permanentlyconnected to an element, which is done by means of soldering or weldingto strips or the like F l.

The second part according to FIGS. 3 and 4 has two parallel spacedprojecting web portions which extend from its base part B II, and areprovided on the surfaces with guiding grooves S which are parallel tothe base part and approximately in the midlength of the projection L II.These guiding grooves and the distance between the segments and theirlength are so dimensioned that an exact fit is obtained when the segmentL I of the first joint part perpendicular to the axial direction of itsbeam element is inserted between the projections L II. The first part isinserted until the plate P rests against the projections LII. In thebase part of the second joint part is a threaded channel K,corresponding to the hole H in the plate P, for a screw S I, as shown inFIG. 5. The second joint part also has strips or the like F II to whichits beam element is attached by means of soldering or welding.

The appearance of the groups of segments is clearly shown in FIGS. 6 and7 which illustrate them in perspective.

If necessary the first joint part may be provided with two or moreprojections L I, and the other joint part may then be provided withadditional projections L II as well so that each part L I can be slidinto a corresponding mating recess on the other part. The guiding stripsand corresponding grooves on the segments may have a different designfrom that shown in the drawings, although this design offers optimumcontrol and reinforcement. The plate P and base part B II may also beprovided with more than one hole if this is necessitated by the width ofthe elements.

Within odontology, the means according to the invention can be used tojoin an extension part and a fixation part in socalled optionallyremovable saddle extension bridges which are used in prosthetic surgery.For this purpose, so-called attachments presently on the market have hadto be used in combination with a screw of a selected dimension. Thesystem according to the invention thus has the advantage that a certainparallel displacement of the joined sections is possible if it shouldprove necessary for some reason after a time. If, for example, the upperpart of the base part B II and segments L II in the second group areground down somewhat, the first group of segments can be insertedsomewhat further and still be attached with the same screw as before.

The device can also be used as attachment plate for the false tooth inresection dentures or as attachment plate for a socalled transversal barfor reconstructions in the upper jaw.

What I claim is:

1. Means for detachably joining two beam elements by a joint which isresistant to bending and torsion forces comprismg,

first and second joints parts each adapted to be permanently secured toa respective one of said two elements, said first joint part including abase portion extending substantially normal to the longitudinal axis ofsaid two beam elements and at least one first web portion projectingoutwardly of said base portion in the direction of said axis,

said first web portion having at least one laterally projecting elongateprotuberance which extends normal to said longitudinal axis,

said second joint part also including a base portion extending normal tosaid longitudinal axis and having at least two parallel-spaced webportions projecting outwardly of the respective base portion,

said two web portions of said second part having a space therebetweenand a projecting length such as to receive with a close fit said firstweb portion of said first part,

at least one of said parallel web portions of said second joint partdefining an elongate recess therein extending normal to saidlongitudinal axis for receiving said protuberance on said first webportion,

whereby said two joint parts may be engaged by sliding said first webpart into the recess defined by said two web portions of said secondjoint part and with said elongate protuberance sliding into saidelongate recess,

said sliding engagement of said two parts occuring in a direction atright angles to said longitudinal axis,

the relative motion of said two joint parts being at right angles tosaid longitudinal axis of said beam elements,

one of said two joint parts including a plate portion generally normalto both the plane of the web portions of said part and to the plane ofthe base portion of said part for limiting the relative motion of saidone joint part to the other joint part.

2. The combination of claim 1 wherein said base and web portion of eachjoint part are integrally formed and said plate is integrally formedwith the base portion and web of the joint part which includes said baseportion.

3. The combination of claim 1 wherein said protuberance is of generallysemicircular cross section and the recess in the web portion of theother part is also of generally semicircular cross section.

4. The combination of claim 3 wherein a protuberance of generallysemicircular cross section is formed on each side of said first web andcorresponding recesses of generally semicircular cross sections areformed on both inside surfaces of said web portions of said second jointpart.

5. The combination of claim 1 in which said protuberance on said firstweb portion is formed thereon at substantially the mid portion of itsprojecting length outwardly of its base portion.

6. The combination of claim 1 which further includes a means forsecuring together said first and second joint parts to prevent theirslidable separation in said direction normal to said longitudinal axis.

1. Means for detachably joining two beam elements by a joint which isresistant to bending and torsion forces comprising, first and secondjoints parts each adapted to be permanently secured to a respective oneof said two elements, said first joint part including a base portionextending substantially normal to the longitudinal axis of said two beamelements and at least one first web portion projecting outwardly of saidbase portion in the direction of said axis, said first web portionhaving at least one laterally projecting elongate protuberance whichextends normal to said longitudinal axis, said second joint part alsoincluding a base portion extending normal to said longitudinal axis andhaving at least two parallel-spaced web portions projecting outwardly ofthe respective base portion, said two web portions of said second parthaving a space therebetween and a projecting length such as to receivewith a close fit said first web portion of said first part, at least oneof said parallel web portions of said second joint part defining anelongate recess therein extending normal to said longitudinal axis forreceiving said protuberance on said first web portion, whereby said twojoint parts may be engaged by sliding said first web part into therecess defined by said two web portions of said second joint part andwith said elongate protuberance sliding into said elongate recess, saidsliding engagement of said two parts occuring in a direction at rightangles to said longitudinal axis, the relative motion of said two jointparts being at right angles to said longitudinal axis of said beamelements, one of said two joint parts including a plate portiongenerally normal to both the plane of the web portions of said part andto the plane of the base portion of said part for limiting the relativemotion of said one joint part to the other joint part.
 2. Thecombination of claim 1 wherein said base and web portion of each jointpart are integrally formed and said plate is integrally formed with thebase portion and web of the joint part which includes said base portion.3. The combination of claim 1 wherein said protuberance is of generallysemicircular cross section and the recess in the web portion of theother part is also of generally semicircular cross section.
 4. Thecombination of claim 3 wherein a protuberance of generally semicircularcross section is formed on each side of said first web and correspondingrecesses of generally semicircular cross sections are formed on bothinside surfaces of said web portions of said second joint part.
 5. Thecombination of claim 1 in which said protuberance on said first webportion is formed thereon at substantially the mid portion of itsprojecting length outwardly of its base portion.
 6. The combination ofclaim 1 which further includes a means for securing together said firstand second joint parts to prevent their slidable separation in saiddirection normal to said longitudinal axis.